In case for Mandarin Chinese, there is Pīnyīn, which is the official transcription into Latin letters of Mandarin Chinese and I agree, so I think it should be transliterated in that system and to get information of this, you can go to: http://en.wikipedia.org/wiki/Pinyin
The Mandarin Chinese latin alphabet
First article of the Universal Declaration of Human Rights
Rénrén shēng ér zìyóu, zài zūnyán hé quánlì shàng yílǜ píngděng. Tāmen fùyǒu lǐxìng hé liángxīn, bìng yīng yǐ xiōngdì guānxì de jīngshén hùxiāng duìdài.